Suspension Clunks - 1996 GP

[quakerj]

I have some suspension clunks, mostly noticeable at low speed, like when driving over a speed bump, pothole in a parking lot, etc.  I don't really hear anything once I get to speed.  Definitely coming from the front, but it sounds like it might be coming from the rear too.

I gave everything a thorough inspection and the only thing I notice is that the front sway bar bushing that bolts to the engine subframe is squeezed real thin on the bottom, looks like it may not even be providing any cushion (see photo).

Since this is a nearly 25 year old car with unknown maintenance history, my plan was to refresh all the suspension components-- new struts, strut mounts, ball joints, tie rod ends, spring seats.  This front suspension setup is foreign to me, I've done a lot of suspension work on other FWD cars, but they were much simpler in design where the strut bolts to the steering knuckle.  I'm not quite sure how to go about this one, all the how-to's I'm finding are just to replace the strut cartridge which seems simple enough.

I assume the whole steering knuckle has to come off-- brakes, axle & ball joint removed, and then the strut & steering knuckle assembly drop down together?  At that point use a spring compressor before removing the center nut of the strut?  Do I have the right idea?  The more I look at it the more of a royal PIA this appears to be and has me wondering if I should just leave the spring seat alone and just replace the strut cartridge.  The spring seat seems fine (no bearing noise either) other than having a fair amount of rust on it.

Also is the rear considered a shock or strut?  Is there still tension there (from the leaf spring) with the car in the air, such that I'll need to use a floor jack or something to relieve the pressure before removing the shock/strut?  Any pointers on the rear would be helpful.

If anyone can give me any tips or point me to some how-to / you-tubes I'd appreciate it.  I have a feeling the sway bar bushing is the root of the clunking problem and that if there is some noise coming from the rear, that replacing the rear shocks/struts will solve it.  But I'd really like to replace all the suspension parts if I can, a 25 year old car could certainly use it.  I have to replace tie-rod ends (boots all tore up), so I'm going to need an alignment anyways, so now is the time to do suspension work.

 

 

Edited September 13, 2020 by quakerj

[rich_e777]

Yeah those are shot, probably the outer ones bolted to the control arms as well. Also you`re pretty much on spot with the disassembly if you wanted to replace the spring seats and the bearing thats somewhere up there too. IIRC there another part called the jounce bumper thats underneath the rubber mount you see once you take the 3 bolt plates or front strut tower brace off if you have one.

I`m doing all that right now, full KYB FE3 front replacement just havent decompressed the springs across the street or into the neighbor's yard yet. I can post pics or P/N if needed. Theres strut bearings and bellow/bumpers available too.

For the back end you are correct, there is still tension on the leaf spring and the FSM calls for a particular tool to use but you can get away doing the job with blocks off wood and a floor jack. The pads on the leaf spring ends, sway bar bushings and the trailing arms are common wear parts, The rear control arms or lateral links are up-gradable to stronger tubular ones from later 2nd Gen W body cars but you have to get two sets of rear links and have one pair modified to fit the front. 

[quakerj]

I bought all the parts so I think I'm going to do the whole thing on the front, I'm not sure the extent of the rust on the spring seat without taking it all apart anyways.  Doesn't sound all that different than a regular FWD car other than the few extra steps of undoing the steering knuckle.  I'll tackle all the sway bar bushings, do these simply bolt on/off, or is there anything else I need to be aware of?  No tension on the sway bar with wheels in the air, correct?

When I bought all my parts on Rockauto, they did not list a jounce bumper, nor can I find one.  If you have a part number that would be most helpful! I bought the spring seats (with bearing), rubber mount up top, boot/bellows, strut cartridge, and that's it if memory serves.  Why does the new top rubber mount come with six nuts (three small, three larger.)?  I only see the three nuts that hold the plate on.

On the rear my leaf spring pads/isolators look to be in good shape, but I will do sway bar bushings while I'm there.  I replaced the trailing arms some time ago, the stock ones were starting to rust through.  Other than compressing the leaf spring a bit, the rear struts are a simple bolt off, back on affair, right?  Should be a few nuts (or bolts) in the trunk, and just the two large nuts holding it down low, is what it looks like to me.

Many thanks for the help!  If you don't mind shooting a few pics if you have time, that would help immensely.

[ron350]

The part # for front strut bumpers are 10250330.

They are still available on ebay for $20 a pop.

 

Your upper strut mount should have a nylon insert on the bottom of the steel plate like in this picture. The GM part # for the mount was 19294067 but they are no longer available. Other brands also have the nylon insert but without a picture how can you tell.

 

 

Edited September 14, 2020 by ron350

[55trucker]

On 9/12/2020 at 10:00 PM, quakerj said:

I assume the whole steering knuckle has to come off-- brakes, axle & ball joint removed, and then the strut & steering knuckle assembly drop down together? 

Also is the rear considered a shock or strut?  Is there still tension there (from the leaf spring) with the car in the air, such that I'll need to use a floor jack or something to relieve the pressure before removing the shock/strut?  Any pointers on the rear would be helpful.

If anyone can give me any tips or point me to some how-to / you-tubes I'd appreciate it.  I have a feeling the sway bar bushing is the root of the clunking problem and that if there is some noise coming from the rear, that replacing the rear shocks/struts will solve it.  But I'd really like to replace all the suspension parts if I can, a 25 year old car could certainly use it.  I have to replace tie-rod ends (boots all tore up), so I'm going to need an alignment anyways, so now is the time to do suspension work.

 

 

 

With respect to just the shock, yes it is a cartridge, the strut assembly remains in the car, you do not remove it. The cartridge is removed from the top thru the opening under the shock tower retaining plate. There is a specific tool which is made use to do the job, it does make the process much easier.

If one is going to do everything related to the front struts then the approach would be the same as any other sealed strut. After disassembling the spring one removes the cap that retains the cartridge inside the strut tube.

The rear is a shock, it doesn't hold the car up. Don't be too quick to blame the rear shocks for noises back there, there is also an anti-roll bar back there as well, check the lateral links for rotted bushings, the trailing arms, also have a look at the springs contact points  (4 of them),  check the exhaust system for clunks as well.

That anti roll bar bushing doesn't look very happy anymore. You'll find some of the regular aftermarket suppliers do make a urethane replacement. The rubber items are not really desirable.

[GoldSupreme95]

This is a good thread. I have just purchased a 95 Olds Cutlass Supreme SL 3.1L with 59,000miles. A nice car but I also have the same clunks. I want to tighten this up and ensure the ride height is accurate and level. I am starting with new tires. Currently the car has 205/65/16 tires fitted. They are old and the wrong size. This week I am fitting either 225/60/16 or possibly 235/60/16.  So I will be interested to hear about the progress and results to eliminate the clunk in the suspension. 

[quakerj]

I have all the parts lined up to do the work, I'm pretty much replacing everything in the suspension system within reason-- struts, bushings, ball joints, mounts, etc.  Waiting until the weather improves enough that I feel like working out in the garage.  By mid-March it's usually wrenching weather here, so it'll get the overhaul soon.

My GP had odd-size tires when I bought it too, I think one was the correct 225/60/16, the others were 215/65/16.  I bought a new set of four soon after I purchased it.  For a 25 year old car it drives nice and tight and handles well.  But it clunks pretty good at low speeds over rough pavement which is driving me crazy.  I'm pretty sure the sway bar bushings are the majority of the problem, I also get a clunk that I can almost feel at the floorboard when I press the brakes lightly, sounds exactly like the sway bar hitting the subframe.

Many of the suspension parts are probably still in serviceable condition, so I might be replacing some stuff just for grins.  But parts for these cars are dirt cheap, lots of closeouts available on Rockauto too.  I'll report back once I start digging into it.

[Bjankins1]

Just changed one of the links in the rear for the exact same issue,turns out my sway bar link on my passenger side wasn't even holding the sway bar, it was bent outwards

[quakerj]

I'm ashamed to say this, but I haven't done a darned thing to the GP suspension since I started this thread.  It's still perfectly driveable and I take it out from time to time.

There's so much rust remediation that's required on the rear (especially the sway bar links), that I put the GP work on hold until I can build my workshop with a lift.  I'd much rather wait a while than be under the car crawling around on my back.  I have concrete poured for the new shop, building materials are here, lift is in storage, just need to put the building up.  But the early hot weather here has made me lose all motivation.  Original schedule was put the building up in early May, but I could write a whole story about construction material (especially cement/concrete) and labor shortages.

I'll get it erected eventually (steel frame bolt together building), and then work on the GP will begin once I get electric & the lift set up.  I have all the parts to do a complete suspension overhaul front and rear.  A bonus is the GP officially reached antique status in the state of KY; got historic plates for it, and now my annual registration should be less than a dollar a year.

Edited July 11, 2022 by quakerj